In many liquid systems, especially those systems which include surface-active compounds which are intentionally included constituents, or even unwanted constituents, it is possible for problems to occur as a result of foaming, either in the manufacture of the composition, the use of the composition or both. For example, compositions such as polymer latexes and latex paints can exhibit a tendency toward foaming because they contain surface active agents such as soaps and/or synthetic detergents. In many cases, such compositions produce excessive foam, and substances known as defoamers, defoaming agents or anti-foaming agents are used to reduce the foaming to an acceptable level for the intended use. Defoaming agents are sometimes also used for liquid systems that are contacted with gaseous substances, such as during the gassing of waste waters, during the intensive stirring of liquids, during distillation, washing or coloring operations or during dispensing processes, for example.
Although the defoaming agents must be able to help control or minimize the amount of foaming that occurs in the intended application, it is also important that such materials do not have a negative impact on the functional properties of the materials with which they are used. Thus, for example, an antifoaming agent which effectively eliminates or minimizes foaming in a latex paint but which makes the paint not properly spreadable because of changes in viscosity, for example, would not be acceptable.
The defoaming agents that have heretofore been used have typically included an active ingredient and a carrier material, among other possible components. Applicants have found and have come to appreciate that many prior defoaming agents have a potentially significant disadvantage in that they comprise or consist of volatile organic compounds (VOC) and/or are not able to achieve high levels of defoaming performance without negatively impacting the performance of the composition with which it will be used.